1. Field of the Invention
This invention relates to an edge-of-dock leveler which acts as a bridge between a loading dock platform and the bed of a carrier and, more particularly, to an apparatus for operating an edge-of-dock leveler for positioning the dock leveler at selected positions relative to an adjacent loading dock platform.
2. Description of Related Art
Dock levelers for bridging a gap between a loading dock platform and a carrier bed are in widespread use for facilitating the loading and unloading of various types of carriers. Forklift trucks are often required to move from a loading dock directly into and out of the storage compartment of a carrier. In order to facilitate such an operation, dock levelers are used to compensate for any height variation which exists between a loading dock platform and the bed of a carrier.
Typically, an edge-of-dock leveler will have a center plate which pivots relative to an adjacent loading dock platform and a lip plate which pivots relative to the center plate. The lip plate will rest directly on the bed of a carrier when a dock leveler is positioned as a bridge. The manual effort required to pivot the center plate and lip plate is often reduced by the use of counterbalance spring mechanisms which are employed to assist in positioning the plates. For example, U.S. Pat. No. 4,665,579 discloses a counterbalance mechanism for an edge-of-dock leveler.
To prevent an operator from injuring his back and to eliminate the lifting effort required to position the dock leveler, a prior art system has been developed that does not require an operator to actually lift the center or lip plates. Instead, an apparatus is utilized so that an operator can position the dock leveler with a push/pull motion. Such an apparatus is disclosed in U.S. Pat. No. 4,689,846.
A problem created by the use of a push/pull apparatus, such as that disclosed in U.S. Pat. No. 4,689,846, is that the operating lever is typically positioned in an awkward manner when the dock leveler is in the stored or bridging positions. This requires that the operator lean over the dock to grasp the operating lever and initially move the dock leveler from the stored or bridging positions. Because the operator is forced to lean over the dock to grasp the operating lever, the operator is at risk of losing his balance and falling over the loading dock. Additionally, the operator is more susceptible to back strain and other back injuries resulting from the awkward positioning of the operating lever.
In addition to the awkward forward position of the operating lever when the dock leveler is in the bridging or stored positions, the operating lever is similarly in an awkward position when the center plate is pivoted to its full rearward position. Specifically, when the center plate is in the full rearward position, the operating lever is typically at a very low angle with respect to the loading dock platform. The operating lever is essentially flush with the ground. This requires that the operator bend over to grasp and hold the operating lever. Again, such a system renders the operator vulnerable to back injuries.
To minimize the need for an operator to bend over to grasp the operating handle when the dock leveler is in the rearward position, it is known to utilize a bent operating lever which has an upper portion angled toward the operator. Such bent operating levers, however, exacerbate the awkward position of the operating lever at times when the dock leveler is in the stored or bridging positions.